4low works but 4hi doesnt

[beer-toe]

Sorry guys I hate to beat a dead horse but Ive searched other posts on this forum and other forums and im having no luck feel like im going in circles.

quick rundown I have a 99 sr5 auto with J shifter.

When I shift the truck into 4hi nothing happens, .No indicator light comes on and the truck is not in 4wd. When i try to shift into 4 low with engine running the truck grinds and sound awful. So what i do is turn the truck off, then shift into im 4wd low and turn the truck back on. When i do this i get my indicator light and the truck is 4wd and works.

So far this is what i have done to pinpoint my issue......


Truck in 4wd the driveshaft is locked up...

Pulled the vsv hoses from the driver side fender well and I do infact have vaccum preset at one of the valves.

Help please.. winter this year i went to the mountains to take the family tubing, and when i arrived and put it in 4hi it didnt work and had 0 traction in the snowed in parking lot.

Next year we are planning on another snow trip and i want i want to get this figured well before we go...

thanks guys i hope somone can chime in and point me in a good direction to start.

 

[BankRunner]

Has the transmission or t-case been out? I had a similar issue after having the clutch done. A pin pulled out of one of the plugs on the outside the trans. Took a while to track it down but fairly easy fix once they figured it out.

 

[beer-toe]

Bought the truck used and the only thing noted was a motor was swapped

 

[HiluxSurf SSR-G]

check the transfer case for a disconnected sensor or switch. could have been disconnected during the engine swap and had gone unnoticed or forgotten. Just try to wiggle and push those connectors in the transfer case just to be sure.

btw, when shifting to and from 4Low, you need to have the transmission in neutral and, if the TC shifter has a neutral position, pause at neutral before shifting to and from 4Low. No need to place the tranny in neutral when shifting to and from 4Hi

 

[beer-toe]

Checked the plugs and connections and everything is plugged in

 

[TheDurk]

Checked the plugs and connections and everything is plugged in

Bad position switch. Just because the driveshaft is locked up in 4lo means nothing. The J-shift will lock it from the TC end, but the front diff will not engage. Did you try and drive it (briefly) on asphalt? If it's really in 4wd you will feel it bind when you turn.

I have the same rig and I had the same issue. Fixing the position switch resolved it. They just lose continuity sometimes. I think it's the one on the passenger side, but it was a few years ago. I could have it backwards. There are two, high on the back of the TC. Major pain to get to. Memory says 27mm wrench but I won't guarantee that either.

 

[beer-toe]

Bad position switch. Just because the driveshaft is locked up in 4lo means nothing. The J-shift will lock it from the TC end, but the front diff will not engage. Did you try and drive it (briefly) on asphalt? If it's really in 4wd you will feel it bind when you turn.

I have the same rig and I had the same issue. Fixing the position switch resolved it. They just lose continuity sometimes. I think it's the one on the passenger side, but it was a few years ago. I could have it backwards. There are two, high on the back of the TC. Major pain to get to. Memory says 27mm wrench but I won't guarantee that either.

I dront notice any change on asphalt..... do you perhaps have a,diagram or part # I could reference off of? Thank you [MENTION=10169]TheDurk[/MENTION] I've seen you posting on other threads similar to mine and hoped you would chime in

 

[TheDurk]

I dront notice any change on asphalt..... do you perhaps have a,diagram or part # I could reference off of? Thank you [MENTION=10169]TheDurk[/MENTION] I've seen you posting on other threads similar to mine and hoped you would chime in

So that proves my point. The 4Lo gearbox engages, but the front diff does not. It could also be the VSVs or the vacuum system, but I'd bet on that position switch.

Here's a link to a diagram, that isn't much help.

http://japan-parts.eu/toyota/us/1999/4runner/vzn185l-gkmgka/3_671460_007_/electrical/8401_switch-relay-computer?pnn=84222B&pa=%2084222-35080

Put your VIN into that site to get the part numbers. You have an auto, so I don't know exactly which switch it is. To confirm that it is in the electric part, use this troubleshooting routine I have posted a dozen times:

Don't guess at it, troubleshoot! Start at the twin VSV's (Vacuum Switching Valves) on the driver fender wall. There are two long vacuum hoses that come up from the diff, one goes to each VSV. Check to see that one of the two hose nipples on the VSV’s has vacuum (engine running, 4WD NOT engaged). If no vacuum either side, check the check valve going to the intake manifold and look for loose hoses or a hole in the reservoir. If there is vacuum going to one hose, then put it in 4WD. See if the vacuum switches to the other hose. If it does, and no 4WD, problem is the diff actuator or the line to the diff. If it does not, then just switch the hoses and you should go into 4WD. This confirms diff is okay. (Mark the hoses first so you know which belongs where!)

OK, switch them back. Then use a test light to see if electrical signal from the TC also switches sides of the VSV. If it does not, problem is the TC, the switch on the TC, or the TC actuator, or its wiring back to the button (last two for non-J shift only). If it does, but the vacuum does not, the problem is the VSV itself.

I start troubleshooting at the VSV's because you can figure out where the trouble is without having to climb under the truck. [Does not apply to '01-'02]

So in your case, if 4wd engages by switching the hoses, but the electric does not switch sides, it is one of the transfer switches. I'd just test them all. Or somebody who has an auto with the J-shift may be able to tell you.

 

[beer-toe]

So that proves my point. The 4Lo gearbox engages, but the front diff does not. It could also be the VSVs or the vacuum system, but I'd bet on that position switch.

Here's a link to a diagram, that isn't much help.

TOYOTA 4RUNNERVZN185L-GKMGKA - ELECTRICAL - SWITCH RELAY COMPUTER | Japan Parts EU

Put your VIN into that site to get the part numbers. You have an auto, so I don't know exactly which switch it is. To confirm that it is in the electric part, use this troubleshooting routine I have posted a dozen times:



So in your case, if 4wd engages by switching the hoses, but the electric does not switch sides, it is one of the transfer switches. I'd just test them all. Or somebody who has an auto with the J-shift may be able to tell you.

thank you [MENTION=10169]TheDurk[/MENTION] I was able to locate the position switch. I ended up ordering one cost was 17$. the picture shows 2 switches on the passenger side. what i will do when i get it is pull one at a time and test the switch if its bad i will swap it. I rather break them loose when i have a new one and do it at one time, because i hear its a pain to get too.

 

[phattyduck]

When the position switch is working, you will hear a relay click in the passenger footwell as you shift from 2H to 4H. That is the relay that runs the VSVs for the ADD actuator.

You are on the right path with the switch...

And they do look like a pain to get to if they transfer case is in the truck:

-Charlie

 

[beer-toe]

@the durk for reference the part # for the switch I purchased was 84222-12010.

I did some more troubleshooting today under the hood....

2wd engine running I have vacuum on vsv from one side....

4wd hi engine running, the other side on the vsv did not switch and have vacuum. No light and 4wd did not engage.

4wd low engine running I did have vacuum on the other vsv. Light came on and the 4wd worked...
[MENTION=139000]phattyduck[/MENTION] thanks for the picture. Whenever I changed into 4wd I listen for a click but I never heard anything..

The 2 plugs with the wire pigtails are those the position switches? The switch i ordered doesn't have a pigtail on it so does that pigtail come off to be reused?

 

[phattyduck]

@the durk for reference the part # for the switch I purchased was 84222-12010.

I did some more troubleshooting today under the hood....

2wd engine running I have vacuum on vsv from one side....

4wd hi engine running, the other side on the vsv did not switch and have vacuum. No light and 4wd did not engage.

4wd low engine running I did have vacuum on the other vsv. Light came on and the 4wd worked...

[MENTION=139000]phattyduck[/MENTION] thanks for the picture. Whenever I changed into 4wd I listen for a click but I never heard anything..

The 2 plugs with the wire pigtails are those the position switches? The switch i ordered doesn't have a pigtail on it so does that pigtail come off to be reused?

Ouch. Sadly, the switch you ordered is for the front diff, used to indicate the ADD position. Those also go bad sometimes... so it may not be a total loss.

The switch you need is one of the 3 visible at the top of the transfer case there, 2 on the driver's side, 1 on the passenger side. (with pigtails attached, one blue, one green, one black).

Based on my deduction, from wiring diagrams and a search of the forums... you actually need 84222-35110, which is the blue sheathed one on the passenger side.

How the system works is this (for j-shifter cases): Shift into 4H, switch on transfer case closes, which actuates the ADD relay in the passenger footwell, which energizes the ADD VSVs, which move the ADD actuator, which closes the ADD indicator switch, which lights the light on the dash.

-Charlie

 

[TheDurk]

Ouch. Sadly, the switch you ordered is for the front diff, used to indicate the ADD position. Those also go bad sometimes... so it may not be a total loss.

The switch you need is one of the 3 visible at the top of the transfer case there, 2 on the driver's side, 1 on the passenger side. (with pigtails attached, one blue, one green, one black).

Based on my deduction, from wiring diagrams and a search of the forums... you actually need 84222-35110, which is the blue sheathed one on the passenger side.

How the system works is this (for j-shifter cases): Shift into 4H, switch on transfer case closes, which actuates the ADD relay in the passenger footwell, which energizes the ADD VSVs, which move the ADD actuator, which closes the ADD indicator switch, which lights the light on the dash.

-Charlie

You're right about the switches, I think.

As to the bolded, that's the 5-speed. Autos have no ADD relay, control is via the 4wd ECU in the driver kick panel. 5-speeds have no 4wd ECU.

And to be correct, current switches from one VSV to the other, which moves vacuum from one hose to the other, which moves the ADD actuator.

Sorry to be picky.

 

[beer-toe]

You're right about the switches, I think.

As to the bolded, that's the 5-speed. Autos have no ADD relay, control is via the 4wd ECU in the driver kick panel. 5-speeds have no 4wd ECU.

And to be correct, current switches from one VSV to the other, which moves vacuum from one hose to the other, which moves the ADD actuator.

Sorry to be picky.

[MENTION=139000]phattyduck[/MENTION] I realized I ordered the wrong one after I seen your picture.... I found the same part I needed with the same part number you posted

Thank you [MENTION=139000]phattyduck[/MENTION] [MENTION=10169]TheDurk[/MENTION] you guys have been awesome wish I could pay my respect back to you....

One last stupid question not knowing exactly which switch/sensor how can I tell which one is the bad one? Lol they don't look fun to get too

 

[phattyduck]

You're right about the switches, I think.

As to the bolded, that's the 5-speed. Autos have no ADD relay, control is via the 4wd ECU in the driver kick panel. 5-speeds have no 4wd ECU.

And to be correct, current switches from one VSV to the other, which moves vacuum from one hose to the other, which moves the ADD actuator.

Sorry to be picky.

The ADD relay is on all j-shift trucks, auto or manual trans. So, all '01/'02 and all Limiteds have the 4WD ECU, but '98-'00 base and SR5 autos just have the relay.

Went back over the diagrams... I'm surprised that Toyota didn't just use a normally open and a normally closed VSV, then power both when in 4WD and leave them both off in 2WD...

-Charlie

 

[TheDurk]

The ADD relay is on all j-shift trucks, auto or manual trans. So, all '01/'02 and all Limiteds have the 4WD ECU, but '98-'00 base and SR5 autos just have the relay.

Went back over the diagrams... I'm surprised that Toyota didn't just use a normally open and a normally closed VSV, then power both when in 4WD and leave them both off in 2WD...

-Charlie

Yeah, you're right, Charlie. The 4wd ECU goes with the push-button TC, not the auto trans. I should have thought about who was posting, but I was watching my Yankees in a Wild Card elimination game and can't be held responsible. Not a good time to post. Sorry.

One explanation on the VSVs is, is that the Toyota setup cuts vacuum to both sides of the actuator when the key is turned off, leaving the actuator locked where it is until the next time the engine is started. Your way, it would kick back to 2wd when power is cut while in 4wd, and then need to reengage the diff back to 4wd when restarted. Remember there is a vacuum reservoir and a check-valve in the system, so the actuator will still move if the VSV is opened up even if the engine is not running. Not what you want when you stall on the edge of slipping off into the bottomless abyss.

 

[phattyduck]

One explanation on the VSVs is, is that the Toyota setup cuts vacuum to both sides of the actuator when the key is turned off, leaving the actuator locked where it is until the next time the engine is started. Your way, it would kick back to 2wd when power is cut while in 4wd, and then need to reengage the diff back to 4wd when restarted. Remember there is a vacuum reservoir and a check-valve in the system, so the actuator will still move if the VSV is opened up even if the engine is not running. Not what you want when you stall on the edge of slipping off into the bottomless abyss.

That's a good enough explanation for me!

-Charlie

 

[beer-toe]

So I replaced 84222-35110 and it didn't work......... I have tested in a open area but in the driveway I was unsuccessful.....

Should I replace the 2nd switch?

 

[beer-toe]

84222-35080 Is this the right part numberfir the 2nd switch?

 

[phattyduck]

Before spending more money, I would suggest getting a multimeter and a friend to help diagnose this...

For the 3 switches on the transfer case, one will close/short in any "4WD" postion (down, right and halfway up, and right and all the way up). One will close/short only in the neutral position (halfway up to 4L) and one will close/short only 4L.

Make sure you can find each one and it is working like it should.

-Charlie